Funny you say that. Noticed that a few years back. 15w40 rotella made my engine sound crazy. Dropped to 5w40 rotella, been happy ever since...

 

Rewired a knock sensor and did some poking around with an extension to see if I could better pinpoint the sound. Seems like it is loudest around #7 which is also burning oil. Not sure if there is any correlation. I'm starting to think it's not a liner because of the speed. It's about 2 taps per second and it doesnt go away above 1500 but the engine starts to drown it out. Also I pulled plug wires and had no change still tapped. Through the extension it sounds like an aluminum bat on concrete. I guess now it's a ting not a tap lol.

 

The tick in mine sometimes sounded louder on top and sometimes louder on the bottom. So it won't necessarily sound louder anywhere. It's pretty much right in the center of the engine.
Mine didn't spin, it just fell the f@ck out! It didn't effect the oiling at all, it still has the same size hole there with or without the bearing in place.
My tick would usually go away right around 1500 rpm too. It definitely, 100% was NOT a slipped liner. As soon as I pulled the bearing out, the tick stopped and never came back.

 

Update time.
So I went ahead and did my head gaskets and found a mess on cylinder 7. Valves were covered in burnt oil and the exhaust valve wasn't seating. I tore the head down put in new stem seals and cleaned and lapped the valves. Got her back together today and the sound is gone, at least for now. I was glad to see all of the sleeves were where they should be. It was actually quite clean in there minus the bad cylinder. Figured I would update for anyone with similar symptoms.

 

you need to do an oil pressure test and see what pressure you are getting hot and cold